Many electrical and mechanical parts in this chassis have special safety-related characteristics. These parts are identified by in the
Schematic Diagram and Exploded View.
It is essential that these special safety parts should be replaced with the same components as recommended in this manual to prevent
Shock, Fire, or other Hazards.
Do not modify the original design without permission of manufacturer.
General Guidance
An isolation Transformer should always be used during the
servicing of a receiver whose chassis is not isolated from the AC
power line. Use a transformer of adequate power rating as this
protects the technician from accidents resulting in personal injury
from electrical shocks.
It will also protect the receiver and it's components from being
damaged by accidental shorts of the circuitry that may be
inadvertently introduced during the service operation.
If any fuse (or Fusible Resistor) in this TV receiver is blown,
replace it with the specified.
When replacing a high wattage resistor (Oxide Metal Film Resistor,
over 1 W), keep the resistor 10 mm away from PCB.
Keep wires away from high voltage or high temperature parts.
Before returning the receiver to the customer,
always perform an AC leakage current check on the exposed
metallic parts of the cabinet, such as antennas, terminals, etc., to
be sure the set is safe to operate without damage of electrical
shock.
Leakage Current Cold Check(Antenna Cold Check)
With the instrument AC plug removed from AC source, connect an
electrical jumper across the two AC plug prongs. Place the AC
switch in the on position, connect one lead of ohm-meter to the AC
plug prongs tied together and touch other ohm-meter lead in turn to
each exposed metallic parts such as antenna terminals, phone
jacks, etc.
If the exposed metallic part has a return path to the chassis, the
measured resistance should be between 1 MΩ and 5.2 MΩ.
When the exposed metal has no return path to the chassis the
reading must be infinite.
An other abnormality exists that must be corrected before the
receiver is returned to the customer.
Leakage Current Hot Check(See below Figure)
Plug the AC cord directly into the AC outlet.
Do not use a line Isolation Transformer during this check.
Connect 1.5 K / 10 watt resistor in parallel with a 0.15 uF capacitor
between a known good earth ground (Water Pipe, Conduit, etc.)
and the exposed metallic parts.
Measure the AC voltage across the resistor using AC voltmeter
with 1000 ohms/volt or more sensitivity.
Reverse plug the AC cord into the AC outlet and repeat AC voltage
measurements for each exposed metallic part. Any voltage
measured must not exceed 0.75 volt RMS which is corresponds to
0.5 mA.
In case any measurement is out of the limits specified, there is
possibility of shock hazard and the set must be checked and
repaired before it is returned to the customer.
CAUTION: Before servicing receivers covered by this service
manual and its supplements and addenda, read and follow the
SAFETY PRECAUTIONS on page 3 of this publication.
NOTE: If unforeseen circumstances create conict between the
following servicing precautions and any of the safety precautions
on page 3 of this publication, always follow the safety precautions.
Remember: Safety First.
General Servicing Precautions
1. Always unplug the receiver AC power cord from the AC power
source before;
a. Removing or reinstalling any component, circuit board mod-
ule or any other receiver assembly.
b. Disconnecting or reconnecting any receiver electrical plug or
other electrical connection.
c. Connecting a test substitute in parallel with an electrolytic
capacitor in the receiver.
CAUTION: A wrong part substitution or incorrect polarity
installation of electrolytic capacitors may result in an explosion hazard.
2. Test high voltage only by measuring it with an appropriate
high voltage meter or other voltage measuring device (DVM,
FETVOM, etc) equipped with a suitable high voltage probe.
Do not test high voltage by "drawing an arc".
3. Do not spray chemicals on or near this receiver or any of its
assemblies.
4. Unless specied otherwise in this service manual, clean
electrical contacts only by applying the following mixture to the
contacts with a pipe cleaner, cotton-tipped stick or comparable
non-abrasive applicator; 10 % (by volume) Acetone and 90 %
(by volume) isopropyl alcohol (90 % - 99 % strength)
CAUTION: This is a ammable mixture.
Unless specied otherwise in this service manual, lubrication of
contacts in not required.
5. Do not defeat any plug/socket B+ voltage interlocks with which
receivers covered by this service manual might be equipped.
6. Do not apply AC power to this instrument and/or any of its
electrical assemblies unless all solid-state device heat sinks are
correctly installed.
7. Always connect the test receiver ground lead to the receiver
chassis ground before connecting the test receiver positive
lead.
Always remove the test receiver ground lead last.
8. Use with this receiver only the test xtures specied in this
service manual.
CAUTION: Do not connect the test xture ground strap to any
heat sink in this receiver.
Electrostatically Sensitive (ES) Devices
Some semiconductor (solid-state) devices can be damaged easily by static electricity. Such components commonly are called
Electrostatically Sensitive (ES) Devices. Examples of typical ES
devices are integrated circuits and some eld-effect transistors
and semiconductor “chip” components. The following techniques
should be used to help reduce the incidence of component damage caused by static by static electricity.
1. Immediately before handling any semiconductor component or
semiconductor-equipped assembly, drain off any electrostatic
charge on your body by touching a known earth ground. Alternatively, obtain and wear a commercially available discharging
wrist strap device, which should be removed to prevent potential shock reasons prior to applying power to the unit under test.
2. After removing an electrical assembly equipped with ES
devices, place the assembly on a conductive surface such as
aluminum foil, to prevent electrostatic charge buildup or exposure of the assembly.
3. Use only a grounded-tip soldering iron to solder or unsolder ES
devices.
4. Use only an anti-static type solder removal device. Some solder
removal devices not classied as “anti-static” can generate
electrical charges sufcient to damage ES devices.
5. Do not use freon-propelled chemicals. These can generate
electrical charges sufcient to damage ES devices.
6. Do not remove a replacement ES device from its protective
package until immediately before you are ready to install it.
(Most replacement ES devices are packaged with leads electrically shorted together by conductive foam, aluminum foil or
comparable conductive material).
7. Immediately before removing the protective material from the
leads of a replacement ES device, touch the protective material
to the chassis or circuit assembly into which the device will be
installed.
CAUTION: Be sure no power is applied to the chassis or circuit,
and observe all other safety precautions.
8. Minimize bodily motions when handling unpackaged replacement ES devices. (Otherwise harmless motion such as the
brushing together of your clothes fabric or the lifting of your
foot from a carpeted oor can generate static electricity sufcient to damage an ES device.)
General Soldering Guidelines
1. Use a grounded-tip, low-wattage soldering iron and appropriate
tip size and shape that will maintain tip temperature within the
range or 500 °F to 600 °F.
2. Use an appropriate gauge of RMA resin-core solder composed
of 60 parts tin/40 parts lead.
3. Keep the soldering iron tip clean and well tinned.
4. Thoroughly clean the surfaces to be soldered. Use a mall wirebristle (0.5 inch, or 1.25 cm) brush with a metal handle.
Do not use freon-propelled spray-on cleaners.
5. Use the following unsoldering technique
a. Allow the soldering iron tip to reach normal temperature.
(500 °F to 600 °F)
b. Heat the component lead until the solder melts.
c. Quickly draw the melted solder with an anti-static, suction-
type solder removal device or with solder braid.
CAUTION: Work quickly to avoid overheating the circuit
board printed foil.
6. Use the following soldering technique.
a. Allow the soldering iron tip to reach a normal temperature
(500 °F to 600 °F)
b. First, hold the soldering iron tip and solder the strand against
the component lead until the solder melts.
c. Quickly move the soldering iron tip to the junction of the
component lead and the printed circuit foil, and hold it there
only until the solder ows onto and around both the component lead and the foil.
CAUTION: Work quickly to avoid overheating the circuit
board printed foil.
d. Closely inspect the solder area and remove any excess or
Some chassis circuit boards have slotted holes (oblong) through
which the IC leads are inserted and then bent at against the circuit foil. When holes are the slotted type, the following technique
should be used to remove and replace the IC. When working with
boards using the familiar round hole, use the standard technique
as outlined in paragraphs 5 and 6 above.
Removal
1. Desolder and straighten each IC lead in one operation by
gently prying up on the lead with the soldering iron tip as the
solder melts.
2. Draw away the melted solder with an anti-static suction-type
solder removal device (or with solder braid) before removing
the IC.
Replacement
1. Carefully insert the replacement IC in the circuit board.
2. Carefully bend each IC lead against the circuit foil pad and
solder it.
3. Clean the soldered areas with a small wire-bristle brush.
(It is not necessary to reapply acrylic coating to the areas).
1. Remove the defective transistor by clipping its leads as close
as possible to the component body.
2. Bend into a "U" shape the end of each of three leads remaining
on the circuit board.
3. Bend into a "U" shape the replacement transistor leads.
4. Connect the replacement transistor leads to the corresponding
leads extending from the circuit board and crimp the "U" with
long nose pliers to insure metal to metal contact then solder
each connection.
Power Output, Transistor Device
Removal/Replacement
1. Heat and remove all solder from around the transistor leads.
2. Remove the heat sink mounting screw (if so equipped).
3. Carefully remove the transistor from the heat sink of the circuit
board.
4. Insert new transistor in the circuit board.
5. Solder each transistor lead, and clip off excess lead.
6. Replace heat sink.
Diode Removal/Replacement
1. Remove defective diode by clipping its leads as close as possible to diode body.
2. Bend the two remaining leads perpendicular y to the circuit
board.
3. Observing diode polarity, wrap each lead of the new diode
around the corresponding lead on the circuit board.
4. Securely crimp each connection and solder it.
5. Inspect (on the circuit board copper side) the solder joints of
the two "original" leads. If they are not shiny, reheat them and if
necessary, apply additional solder.
3. Solder the connections.
CAUTION: Maintain original spacing between the replaced
component and adjacent components and the circuit board to
prevent excessive component temperatures.
Circuit Board Foil Repair
Excessive heat applied to the copper foil of any printed circuit
board will weaken the adhesive that bonds the foil to the circuit
board causing the foil to separate from or "lift-off" the board. The
following guidelines and procedures should be followed whenever
this condition is encountered.
At IC Connections
To repair a defective copper pattern at IC connections use the
following procedure to install a jumper wire on the copper pattern
side of the circuit board. (Use this technique only on IC connections).
1. Carefully remove the damaged copper pattern with a sharp
knife. (Remove only as much copper as absolutely necessary).
2. carefully scratch away the solder resist and acrylic coating (if
used) from the end of the remaining copper pattern.
3. Bend a small "U" in one end of a small gauge jumper wire and
carefully crimp it around the IC pin. Solder the IC connection.
4. Route the jumper wire along the path of the out-away copper
pattern and let it overlap the previously scraped end of the
good copper pattern. Solder the overlapped area and clip off
any excess jumper wire.
At Other Connections
Use the following technique to repair the defective copper pattern
at connections other than IC Pins. This technique involves the
installation of a jumper wire on the component side of the circuit
board.
1. Remove the defective copper pattern with a sharp knife.
Remove at least 1/4 inch of copper, to ensure that a hazardous
condition will not exist if the jumper wire opens.
2. Trace along the copper pattern from both sides of the pattern
break and locate the nearest component that is directly connected to the affected copper pattern.
3. Connect insulated 20-gauge jumper wire from the lead of the
nearest component on one side of the pattern break to the lead
of the nearest component on the other side.
Carefully crimp and solder the connections.
CAUTION: Be sure the insulated jumper wire is dressed so the
it does not touch components or sharp edges.
Fuse and Conventional Resistor
Removal/Replacement
1. Clip each fuse or resistor lead at top of the circuit board hollow
stake.
2. Securely crimp the leads of replacement component around
notch at stake top.
This spec. sheet applies to LA54H Chassis applied LED TV all
models manufactured in TV factory
2. Specification
(1) Because this is not a hot chassis, it is not necessary to use
an isolation transformer. However, the use of isolation
transformer will help protect test instrument.
(2) Adjustment must be done in the correct order.
(3) The adjustment must be performed in the circumstance of
25 ±5 ºC of temperature and 65±10% of relative humidity if
there is no specific designation
(4) The input voltage of the receiver must keep 100~240V,
50/60Hz
(5) The receiver must be operated for about 5 minutes prior to
the adjustment when module is in the circumstance of over
15
ºC
In case of keeping module is in the circumstance of 0°C, it
should be placed in the circumstance of above 15°C for 2
hours
In case of keeping module is in the circumstance of below
-20°C, it should be placed in the circumstance of above
15°C for 3 hours.
※ Caution
When still image is displayed for a period of 20 minutes or
longer (especially where W/B scale is strong.
Digital pattern 13ch and/or Cross hatch pattern 09ch), there
can some afterimage in the black level area
3. Adjustment items
3.1. Main PCBA Adjustments
(1) ADC adjustment(OTP) : Component
(2) EDID downloads for HDMI
3.2. Final assembly adjustment
(1) White Balance adjustment
(2) RS-232C functionality check
(3) Factory Option setting per destination
(4) Shipment mode setting (In-Stop)
(5) GND and HI-POT test
4. MAIN PCBA Adjustments
4.1. ADC Adjustment
4.1.1. Overview
- ADC adjustment is needed to find the optimum black level and
gain in Analog-to-Digital device and to compensate RGB
deviation..
4.1.2. Equipment & Condition
(1) Protocol: RS-232C
(2) Inner Pattern
- Resolution : 1080p(Comp) / 1024*768(RGB)
- Pattern : Horizontal 100% Color Bar Pattern
- Pattern level : 0.7±0.1 Vp-p
4.1.3. Adjustment
4.1.3.1. Adjustment method
- Connect to Jig by using RS-232(USB), adjust Component
※ Manual adj (If needed in Final Assembly)
- Required equipment : Adjustment R/C
- Enter Service Mode by pushing “ADJ” key,
- Start ‘OTP’ ADC Type by pushing ‘►’ key at [7. ADC Calibration]
※ In L13 case, Adjust ADC(OTP) is automatically ‘OK’
4.1.3.2. Adj. protocol (only Internal patten)
4.2. EDID Download
4.2.1. Overview
▪ It is a VESA regulation. A PC or a MNT will display an
optimal resolution through information sharing without any
necessity of user input. It is a realization of “Plug and Play”.
4.2.2. Equipment
▪ Since embedded EDID data is used, EDID download JIG,
HDMI cable and D-sub cable are not need.
▪ Adjust by using remote controller
4.2.3. Download method
1) Press Adj. key on the Adj. R/C,
2) Select EDID D/L menu.
3) By pressing Enter key, EDID download will begin
4) If Download is successful, OK is display, but If Download is
failure, NG is displayed.
5) If Download is failure, Re-try downloads.
3.3. Appendix
(1) Shipment conditions
(2) Tool option menu
(3) USB Download (S/W Update, Option and Service only)
(4) Preset CH Information
Only for training and service purposes
- 10 -
※ Caution) When EDID Download, must remove RGB/HDMI
5.1.1.1. W/B adj. Objective & How-it-works
(1) Objective: To reduce each Panel’s W/B deviation
(2) How-it-works: When R/G/B gain in the OSD is at 192, it
means the panel is at its Full Dynamic Range.
● Case : Cool Mode
- To adjust the white balance without the saturation, G gain
should be adjust at least 172 and change the others (R,B
Gain)
▪ When R or B gain is over 255, G gain can be adjust below
172)
● Case : Medium / Warm Mode
- To adjust the white balance without the saturation, Fix the
one of R/G/B gain to 192 (default data) and decrease the
others.
(3) Adj. condition: normal temperature
- Surrounding Temperature: 25 ± 5 °C
- Warm-up time: About 5 Min
- Surrounding Humidity: 20% ~ 80%
- Before White balance adjustment, Keep power on status,
don’t power off
5.1.1.2. Adj. condition and cautionary items
(1) Lighting condition in surrounding area surrounding lighting
should be lower 10 lux. Try to isolate adj. area into dark
surrounding.
(2) Probe location : Color Analyzer (CA-210) probe should be
within 10cm and perpendicular of the module surface
(90 ° ± 2.5 °)
(3) Aging time
- After Aging Start, Keep the Power ON status during 5
Minutes.
- In case of LCD, Back-light on should be checked using no
※ CASE : Cool mode
First adjust the coordinate far away from the target value(x,
y).B
(1) x, y >target
(2) x, y< target
(3) x >target , y< target
(4) x < target , y >target
- Every 4 case have to t y value by adjusting B Gain and
then t x value by adjusting R-Gain
- In this case, increasing/decreasing of B Gain and R Gain
can be adjusted.
► How to adjust
(1) Fix G gain at least 172 : Adjust R, B Gain ( In Case of
Mostly Blue Gain Saturation )
(2) When R or B Gain > 255, Release Fixed G Gain and
Readjust
※ CASE : Medium / Warm mode
First adjust the coordinate far away from the target value(x, y).
(1) x, y >target
i) Decrease the R, G.
(2) x, y< target
i) First decrease the B gain,
ii) Decrease the one of the others.
(3) x >target , y< target
i) First decrease B, so make y a little more than the target.
ii) Adjust x value by decreasing the R
(4) x < target , y >target
i) First decrease B, so make x a little more than the target.
ii) Adjust x value by decreasing the G
5.1.6. Reference (White Balance Adj. coordinate and
color temperature)
▪ Luminance: 204 Gray, 80IRE
** (normal line) LGD Cell
** Except Gumi winter season (Mar ~ Dec) & Global
(1) Check the POWER CABLE and SIGNAL CABE insertion
condition
6.2. GND & HI-POT auto-check
(1) Pallet moves in the station. (POWER CORD / AV CORD is
tightly inserted)
(2) Connect the AV JACK Tester.
(3) Controller (GWS103-4) on.
(4) GND Test (Auto)
- If Test is failed, Buzzer operates.
- If Test is passed, execute next process (Hi-pot test).
(Remove A/V CORD from A/V JACK BOX)
(5) HI-POT test (Auto)
- If Test is failed, Buzzer operates.
- If Test is passed, GOOD Lamp on and move to next process
automatically.
6.3. Checkpoint
(1) Test voltage
- GND: 1.5KV/min at 100mA
- SIGNAL: 3KV/min at 100mA
(2) TEST time: 1 second
(3) TEST POINT
- GND Test = POWER CORD GND and SIGNAL CABLE GND.
- Hi-pot Test = POWER CORD GND and LIVE & NEUTRAL.
(4) LEAKAGE CURRENT: At 0.5mArms
8. Control Key Check UI
8.1. Test method
(1) Condition : Power Only Full White Mode
(2) When you check the operation of control key, appear the UI
such as below figure on TV Screen.
(3) In case of the model applied the joystick type control key
(xxLF56, xxLF55, xxLF60 and xxLF62), the UI Sequence is
CH+, CH-, Vol+, Vol-, Enter and TEST OK such as figure 1.
(4) In case of the model applied rotary switch type (xxLF640R-
NA KR only), the UI Sequence is Channel Up, Channel
Down, Volume Up, Volmue Down, Enter, Test OK, Input
Select and Power such as figure 2.
Fig.1
7. AUDIO output check
7.1. Audio input condition
(1) RF input: Mono, 1KHz sine wave signal, 100% Modulation
(2) CVBS, Component: 1KHz sine wave signal (0.4Vrms)
(3) RGB PC: 1KHz sine wave signal (0.7Vrms)
(1) Put the USB Stick to the USB socket
(2) Automatically detecting update file in USB Stick
- If your downloaded program version in USB Stick is lower
than that of TV set, it didn’t work. Otherwise USB data is
automatically detected.
(3) Show the message “Copying files from memory”
(4) Updating is staring.
(7) In terms of FRC version update, below sequence are the
only for 60LF6000-Ux model.
(a) When the main sw downloading was finished, if FRC
SW version of TV Set is lower than the FRC version
Included in downloading version, FRC verison update
will be started automatically during displaying the below
figure.
(b) Be careful to not be off of TV Power.
(c) Udating the FRC is completed, the TV will restrart
automatically.
(d) Check your updated FRC version on TV set with
pushing “IN-START” key in service remote controller.
(e) In references, FRC version value shown in TV may
differ from below value.
Refer to the BOM aobut the latest FRC version.
(5) Updating Completed, The TV will restart automatically
(6) If your TV is turned on, check your updated version and
Tool option.
* If downloading version is more high than your TV have, TV
can lost all channel data. In this case, you have to channel
recover. If all channel data is cleared, you didn’t have a DTV/
ATV test on production line.
* After downloading, TOOL OPTION setting is needed again.
(1) Push "IN-START" key in service remote controller.
(2) Select "Tool Option 1" and Push “OK” button.
(3) Punch in the number. (Each model has their number.)